diff --git a/Mage.Sets/src/mage/cards/e/ErtaisFamiliar.java b/Mage.Sets/src/mage/cards/e/ErtaisFamiliar.java
new file mode 100644
index 00000000000..bb0b26348ef
--- /dev/null
+++ b/Mage.Sets/src/mage/cards/e/ErtaisFamiliar.java
@@ -0,0 +1,100 @@
+package mage.cards.e;
+
+import mage.MageInt;
+import mage.MageObjectReference;
+import mage.abilities.Ability;
+import mage.abilities.TriggeredAbility;
+import mage.abilities.common.LeavesBattlefieldTriggeredAbility;
+import mage.abilities.common.SimpleActivatedAbility;
+import mage.abilities.common.SourcePhaseOutTriggeredAbility;
+import mage.abilities.costs.mana.ManaCostsImpl;
+import mage.abilities.effects.ContinuousRuleModifyingEffectImpl;
+import mage.abilities.effects.common.MillCardsControllerEffect;
+import mage.abilities.keyword.PhasingAbility;
+import mage.abilities.meta.OrTriggeredAbility;
+import mage.cards.CardImpl;
+import mage.cards.CardSetInfo;
+import mage.constants.*;
+import mage.game.Game;
+import mage.game.events.GameEvent;
+
+import java.util.UUID;
+
+/**
+ * @author Susucr
+ */
+public final class ErtaisFamiliar extends CardImpl {
+
+    public ErtaisFamiliar(UUID ownerId, CardSetInfo setInfo) {
+        super(ownerId, setInfo, new CardType[]{CardType.CREATURE}, "{1}{U}");
+
+        this.subtype.add(SubType.ILLUSION);
+        this.power = new MageInt(2);
+        this.toughness = new MageInt(2);
+
+        // Phasing
+        this.addAbility(PhasingAbility.getInstance());
+
+        // When Ertai's Familiar phases out or leaves the battlefield, mill three cards.
+        TriggeredAbility trigger = new OrTriggeredAbility(
+                Zone.BATTLEFIELD,
+                new MillCardsControllerEffect(3),
+                new SourcePhaseOutTriggeredAbility(null, false),
+                new LeavesBattlefieldTriggeredAbility(null, false)
+        ).setTriggerPhrase("When {this} phases out or leaves the battlefield, ");
+        trigger.setWorksPhasedOut(true);
+        this.addAbility(trigger);
+
+        // {U}: Until your next upkeep, Ertai's Familiar can't phase out.
+        this.addAbility(new SimpleActivatedAbility(
+                new ErtaisFamiliarReplacementEffect(),
+                new ManaCostsImpl<>("{U}")
+        ));
+    }
+
+    private ErtaisFamiliar(final ErtaisFamiliar card) {
+        super(card);
+    }
+
+    @Override
+    public ErtaisFamiliar copy() {
+        return new ErtaisFamiliar(this);
+    }
+}
+
+class ErtaisFamiliarReplacementEffect extends ContinuousRuleModifyingEffectImpl {
+
+    public ErtaisFamiliarReplacementEffect() {
+        super(Duration.UntilYourNextUpkeepStep, Outcome.Neutral);
+        staticText = "until your next upkeep, {this} can't phase out";
+    }
+
+    private ErtaisFamiliarReplacementEffect(final ErtaisFamiliarReplacementEffect effect) {
+        super(effect);
+    }
+
+    @Override
+    public ErtaisFamiliarReplacementEffect copy() {
+        return new ErtaisFamiliarReplacementEffect(this);
+    }
+
+
+    @Override
+    public boolean checksEventType(GameEvent event, Game game) {
+        return event.getType() == GameEvent.EventType.PHASE_OUT;
+    }
+
+    @Override
+    public void init(Ability source, Game game) {
+        super.init(source, game);
+        affectedObjectList.clear();
+        affectedObjectList.add(new MageObjectReference(source.getSourceId(), game));
+        affectedObjectsSet = true;
+    }
+
+    @Override
+    public boolean applies(GameEvent event, Ability source, Game game) {
+        MageObjectReference targetMOR = new MageObjectReference(event.getTargetId(), game);
+        return affectedObjectList.stream().anyMatch(mor -> mor.equals(targetMOR));
+    }
+}
\ No newline at end of file
diff --git a/Mage.Sets/src/mage/sets/Weatherlight.java b/Mage.Sets/src/mage/sets/Weatherlight.java
index ad5e41d063a..a65eb43f367 100644
--- a/Mage.Sets/src/mage/sets/Weatherlight.java
+++ b/Mage.Sets/src/mage/sets/Weatherlight.java
@@ -80,6 +80,7 @@ public final class Weatherlight extends ExpansionSet {
         cards.add(new SetCardInfo("Dwarven Berserker", 97, Rarity.COMMON, mage.cards.d.DwarvenBerserker.class));
         cards.add(new SetCardInfo("Dwarven Thaumaturgist", 98, Rarity.RARE, mage.cards.d.DwarvenThaumaturgist.class));
         cards.add(new SetCardInfo("Empyrial Armor", 13, Rarity.COMMON, mage.cards.e.EmpyrialArmor.class));
+        cards.add(new SetCardInfo("Ertai's Familiar", 38, Rarity.RARE, mage.cards.e.ErtaisFamiliar.class));
         cards.add(new SetCardInfo("Fallow Wurm", 126, Rarity.UNCOMMON, mage.cards.f.FallowWurm.class));
         cards.add(new SetCardInfo("Familiar Ground", 127, Rarity.UNCOMMON, mage.cards.f.FamiliarGround.class));
         cards.add(new SetCardInfo("Fatal Blow", 67, Rarity.COMMON, mage.cards.f.FatalBlow.class));
diff --git a/Mage.Tests/src/test/java/org/mage/test/cards/single/wth/ErtaisFamiliarTest.java b/Mage.Tests/src/test/java/org/mage/test/cards/single/wth/ErtaisFamiliarTest.java
new file mode 100644
index 00000000000..cc35400ba05
--- /dev/null
+++ b/Mage.Tests/src/test/java/org/mage/test/cards/single/wth/ErtaisFamiliarTest.java
@@ -0,0 +1,106 @@
+
+package org.mage.test.cards.single.wth;
+
+import mage.constants.PhaseStep;
+import mage.constants.Zone;
+import org.junit.Test;
+import org.mage.test.serverside.base.CardTestPlayerBase;
+
+/**
+ * @author Susucr
+ */
+public class ErtaisFamiliarTest extends CardTestPlayerBase {
+
+    /**
+     * {@link mage.cards.e.ErtaisFamiliar} <br>
+     * Ertai's Familiar {1}{U} <br>
+     * Creature — Illusion <br>
+     * Phasing <br>
+     * When Ertai’s Familiar phases out or leaves the battlefield, mill three cards. <br>
+     * {U}: Until your next upkeep, Ertai’s Familiar can’t phase out. <br>
+     * 2/2
+     */
+    private final String familiar = "Ertai's Familiar";
+
+    @Test
+    public void test_phaseout() {
+        setStrictChooseMode(true);
+
+        addCard(Zone.HAND, playerA, familiar);
+        addCard(Zone.BATTLEFIELD, playerA, "Island", 2);
+
+        // Casting the familiar for it to not start phasing out turn 1.
+        castSpell(1, PhaseStep.PRECOMBAT_MAIN, playerA, familiar);
+
+        setStopAt(3, PhaseStep.PRECOMBAT_MAIN);
+        execute();
+
+        assertGraveyardCount(playerA, 3);
+        assertPermanentCount(playerA, familiar, 0);
+    }
+
+    @Test
+    public void test_activate_cant_phaseout() {
+        setStrictChooseMode(true);
+
+        addCard(Zone.HAND, playerA, familiar);
+        addCard(Zone.BATTLEFIELD, playerA, "Island", 3);
+
+        // Casting the familiar for it to not start phasing out turn 1.
+        castSpell(1, PhaseStep.PRECOMBAT_MAIN, playerA, familiar);
+
+        activateAbility(1, PhaseStep.POSTCOMBAT_MAIN, playerA, "{U}:");
+
+        setStopAt(3, PhaseStep.PRECOMBAT_MAIN);
+        execute();
+
+        assertGraveyardCount(playerA, 0);
+        assertPermanentCount(playerA, familiar, 1);
+    }
+
+    @Test
+    public void test_activate_cant_phaseout_other_effect() {
+        setStrictChooseMode(true);
+
+        addCard(Zone.HAND, playerA, familiar);
+        // Put a +1/+1 counter on target creature. It phases out.
+        addCard(Zone.HAND, playerA, "Slip Out the Back");
+        addCard(Zone.BATTLEFIELD, playerA, "Island", 4);
+
+        // Casting the familiar for it to not start phasing out turn 1.
+        castSpell(1, PhaseStep.PRECOMBAT_MAIN, playerA, familiar);
+
+        activateAbility(1, PhaseStep.BEGIN_COMBAT, playerA, "{U}:");
+        castSpell(1, PhaseStep.POSTCOMBAT_MAIN, playerA, "Slip Out the Back", familiar);
+
+        setStopAt(3, PhaseStep.PRECOMBAT_MAIN);
+        execute();
+
+        assertGraveyardCount(playerA, 1); // Slip Out the Back
+        assertPermanentCount(playerA, familiar, 1);
+        assertPowerToughness(playerA, familiar, 3, 3);
+    }
+
+    @Test
+    public void test_activate_cant_phaseout_then_blink() {
+        setStrictChooseMode(true);
+
+        addCard(Zone.HAND, playerA, familiar);
+        // Exile target creature you control, then return that card to the battlefield under its owner’s control.
+        // Draw a card.
+        addCard(Zone.HAND, playerA, "Blur");
+        addCard(Zone.BATTLEFIELD, playerA, "Island", 6);
+
+        // Casting the familiar for it to not start phasing out turn 1.
+        castSpell(1, PhaseStep.PRECOMBAT_MAIN, playerA, familiar);
+
+        activateAbility(1, PhaseStep.BEGIN_COMBAT, playerA, "{U}:");
+        castSpell(1, PhaseStep.POSTCOMBAT_MAIN, playerA, "Blur", familiar);
+
+        setStopAt(3, PhaseStep.PRECOMBAT_MAIN);
+        execute();
+
+        assertGraveyardCount(playerA, 3 * 2 + 1); // 2 familiar trigger + Blur
+        assertPermanentCount(playerA, familiar, 0);
+    }
+}
\ No newline at end of file